using System;

namespace HelloSoftUni
{
    class Program
    {
        static void Main(String[] args)
        {
            int aquariumLong = int.Parse(Console.ReadLine());
            int aquariumShort = int.Parse(Console.ReadLine());
            int aquariumHight = int.Parse(Console.ReadLine());
            double percent = double.Parse(Console.ReadLine());

            double neadLiters = ((aquariumLong * aquariumShort * aquariumHight) * 0.001) * (1 - (percent / 100));
            Console.WriteLine(neadLiters);
        }
    }
}